This invention relates to detergent formulations useful in cleaning a variety of substrates, including without limitation hard surfaces, metals, plastics, glass, laundry, dishes, etc. It also relates to components useful in formulating such detergents, wherein the components are surfactants of the sulfosuccinamate type.
Chemical compounds and multi-component formulations containing the same that are useful for removing grease, oils, dirt, and other unwanted matter from various surfaces and objects have been known since early times, and include the simple soaps which are manufactured by oil saponification, a process in which aqueous alkali metal hydroxide is mixed with an ester (such as an animal fat or vegetable oil) to cause its de-esterification and attendant formation of the corresponding alkali salt(s) of the carboxylic acid(s) from which the ester was comprised. Importantly, the anion portions of the water-soluble alkali salts of these carboxylic acid(s) include as part of their molecular structure a polar hydrophilic portion (the carboxylate function) which is highly attracted to and associates well with water molecules. In the same anion, such salts also include a non-polar, hydrophobic portion, which is most often a hydrocarbyl moiety containing between about 12 and 22 carbon atoms per molecule. Such salts are commonly referred to by those skilled in the art as xe2x80x9csalts of fatty acidsxe2x80x9d, and by laypersons as xe2x80x9csoapxe2x80x9d. As used in this specification and the appended claims, xe2x80x9chydrocarbylxe2x80x9d, when referring to a substituent or group is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl substituents or groups include: (1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic radical); (2) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); (3) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group.
Aqueous solutions of salts of fatty acids are very effective at causing grease, oils, and other normally water-insoluble materials to become solubilized by the well-known phenomenon of micelle formation, involving the formation of a water-soluble oil/soap complex, and are thus rendered capable of being rinsed away with water, leaving behind a cleaned substrate, whether it be a tabletop, countertop, article of glassware or dinnerware, flatware, objects of art, statues, clothing, architecture, motor vehicles, skin, hair, etc. Factors which are most readily varied in the manufacture of soap include the selection of the particular oil which is to be saponified, as it is well-known that different oils comprise varying amounts of individual components having differing lengths of hydrocarbyl moieties in the finished anion. Thus, an oil may be selected for a specific use.
While the industries for the production of such soaps from fats and oils are well-established, saponification chemists and other workers have continuously sought improved chemistries for rendering materials which are not normally soluble in aqueous media to be rendered soluble therein. Towards this end, a wide variety of materials have been identified by those who have become skilled in such arts, with the common denominator of such materials being that the materials useful as surfactants all contain a hydrophobic portion and a hydrophilic portion in their molecular structures.
One family of materials that have been identified as suitable soap substitutes are the linear alkylbenzene (xe2x80x9cLABxe2x80x9d) sulfonates. The LAB sulfonates in general are exemplified as comprising a benzene ring structure having both a non-polar hydrocarbyl substituent and a polar sulfonate group bonded to the ring. Factors which are most readily varied in the manufacture of LAB type detergents include the length of the hydrocarbon chain of the alkyl substituent, the positional isomeric relationship between the hydrocarbyl group and the sulfonate group (o, p, m) on the ring, and the location of the point of attachment of the ring to a hydrocarbyl chain substituent, as discussed in U.S. Pat. Nos. 6,133,492; 5,847,254; 5,777,187; and 5,770,782, the contents of each of which are herein incorporated by reference thereto.
Sulfosuccinamides are a well-known class of surfactants which are made by reacting a primary amine with maleic acid anhydride and then sulfonating the resulting product with sulfite ion. Sulfosuccinamides are used in industrial applications. N-tallowyl sulfosuccinamide is used primarily in emulsion polymerization where it imparts small particle and mechanical stability to the latex. Such materials are typically pastes having a 35% actives content in water, which makes them somewhat difficult to handle and process. Sulfosuccinamides are also used as foaming agents in SBR latex for carpet backing and as emulsifying agents for wax and oil polishes. The prior art is relatively devoid of much activity in the area of these types of surfactants.
The general classes of surfactants described above are but three of the thousands of known surfactant materials. In general terms, the selection of a particular surfactant for an intended use will depend upon several factors, such as: cost, effectiveness, compatibility with other materials, toxicity, biodegradability, environmental impact, aesthetics, etc. Thus, the selection of a particular material is based upon an overall favorable mix of several variables, and what may be a preferred material for one given end use is not in all substantial likelihood preferred for a different use. Of the surfactants in the prior art, those which exhibit excellent soil removal, compatibility with a wide range of materials, stability, existence in the liquid state when neat, low streaking, little film formation, and excellent laundry cleaning performance, all at a reasonable cost, are relatively scarce. In accordance with the present invention are provided sulfosuccinamate detergents possessive of all of these properties. Low viscosity, liquid products can be made which have excellent detergency properties and high water hardness tolerance.
The present invention provides compositions of matter useful as surfactants in finished formulations for cleaning dishes, hard surfaces, and laundry, and other uses which surfactants are known, which comprises an anionic form of a material described by the formula: 
in which R1 is a hydrocarbyl group containing between 5 and 19 carbon atoms, saturated or unsaturated, straight-chain, branched, or cyclic; R2 and R3 may each independently be a hydrogen, or a hydrocarbyl group selected from the group consisting of: methyl and ethyl; x may be any integer between 1 and 20, including 1 and 20; R4 and R5 may each independently be a hydrogen, or a hydrocarbyl group selected from the group consisting of: methyl and ethyl; and y is independently equal to zero or 1.